# all the nations

"the people of all the nations"

# have drunk the wine of her immoral passion

"have become sexually immoral like her" or "have become drunk like her in sexual sin" 

# her immoral passion

Babylon is spoken of as if it were a prostitute who has caused other people to sin along with her. This may well have a double meaning: literal sexual immorality and also the worship of false gods.

# merchants

A merchant is a person who sells things.

# from the power of her sensual way of living

"because she spent so much money on sexual immorality"